Gas flow regulator valve

Abstract

An improved fluid control valve assembly employing a needle valve integrally formed on a non-rotating valve stem includes a metering orifice for engaging and forming a fluid seal with the valve needle, and a generally radially extending end face on the valve stem for engaging an opposing wall surface acting to positively stop the valve stem upon fully closing the valve and forming a seal between the metering orifice and valve needle to thereby avoid excessive loads and wear between the metering orifice and valve needle.

What is claimed is: 
     
       1. A fluid control valve assembly comprising a valve body having a bore formed therein terminating in an end wall and a counterbore coaxial with said bore and having internal threads formed therein,   a valve guide having a cylindrical valve chamber formed therein, said valve guide having first and second external thread means thereon with said first external threads engaging the internal threads in said counterbore for mounting said valve guide on said valve body,   an inlet port in said valve body communicating with said bore,   an outlet port in said valve body,   a fluid passage coaxial with said valve chamber and said bore extending from said end wall and communicating with said outlet port,   a non-rotating valve stem mounted in said valve guide chamber for axial movement therein, said valve stem having an outer end extending outwardly from said valve guide and an inner end having a substantially radial face and a valve needle integrally formed on and projecting axially from said substantially radial face coaxially with said valve chamber and said valve stem,   a valve seat mounted within said valve chamber, said valve seat having a first surface complementary to and engaging said end wall and a second generally radial surface disposed in opposition to said substantially radial face,   a metering orifice formed in and extending through said valve seat in coaxial relation with said valve stem and said valve needle, said metering orifice communicating with said fluid passage and being dimensioned to receive and cooperate with said needle valve to provide flow control through the valve from said inlet port to said outlet port when said valve stem is moved from the closed position and to engage and provide a seal with the valve needle when the valve stem is in the closed position, and   actuator wheel means axially fixed on the outer end of said valve stem for substantially free rotation thereon, said actuator wheel means including internal thread means engaging and cooperating with said second external thread means on said valve guide whereby rotation of the actuator wheel means will produce axial movement of the valve stem to move the valve stem between the open and closed positions.   
     
     
       2. The valve assembly defined in claim 1 wherein said substantially radial face on said valve stem engages said substantially radial surface on said valve seat and cooperates therewith to provide a positive stop for said valve stem when the valve is in the closed position. 
     
     
       3. The valve assembly defined in claim 1 wherein said valve seat has a diameter substantially equal to the diameter of the bore in said valve body, and wherein said valve guide has an open inner end portion engaging said valve seat around its peripheral edge portion to retain said first surface in engagement with said end wall. 
     
     
       4. The valve assembly defined in claim 3 further comprising means defining a fluid passage extending through the inner end portion of said valve guide providing fluid communication between said inlet and said valve chamber. 
     
     
       5. The valve assembly defined in claim 4 wherein said substantially radial face on said valve stem engages said substantially radial surface on said valve seat and cooperates therewith to provide a positive stop for said valve stem when the valve is in the closed position. 
     
     
       6. The valve assembly defined in claim 5 wherein said valve seat is integrally molded from a low friction synthetic resin material. 
     
     
       7. The valve assembly defined in claim 6 further comprising O-ring means providing a fluid seal between said valve stem and said valve guide. 
     
     
       8. The valve assembly defined in claim 7 further comprising snap ring means releasably mounting said actuator wheel means on said valve stem. 
     
     
       9. The valve assembly defined in claim 2 wherein said valve needle and said metering orifice are dimensioned to provide a substantially line-contact seal immediately prior to said substantially radial face contacting said substantially radial surface upon closing the valve, and wherein said substantially radial face and said substantially radial surface cooperate to increase sealing of the valve upon application of increase closing force by rotation of said actuator wheel whereby valve seat distortion and valve needle wear are reduced. 
     
     
       10. The valve assembly defined in claim 1, wherein said valve needle and said substantially radial face on said valve stem comprise sealing means for minimizing damage and wear by first initializing the seal by line contact on the valve stem and then as closing force is increased, providing increased sealing by establishing the sealing on the said radial face. 
     
     
       11. The valve assembly as defined in claim 1, further including means for the transfer of load from said stem to said radial face for minimizing distortion and valve wear. 
     
     
       12. The valve assembly as defined in claim 10, further including means for the transfer of load from said stem to said radial face for minimizing distortion and valve wear. 
     
     
       13. A fluid control valve assembly comprising a valve body having a bore formed therein terminating in the valve body, and a counterbore coaxial with said bore and having internal threads formed therein,   a valve guide having a cylindrical valve chamber formed therein, said valve guide having first and second external thread means formed thereon with said first external thread means engaging the internal threads in said counterbore for mounting said valve guide on said valve body and having an open inner end disposed within said bore,   an inlet port in said valve body communicating with said bore,   an outlet port in said valve body,   a non-rotating valve stem mounted in said valve guide chamber for axial movement therein, said valve stem having an outer end extending outwardly from said valve guide and an inner end having a substantially radial face and a valve needle integrally formed on and projecting axially from said substantially radial face coaxially with said valve chamber and said valve stem,   a valve seat having a generally radial surface disposed in opposition to said radial face,   a metering orifice formed in and extending through said valve seat in coaxial relation with said valve stem and said valve needle, said metering orifice providing fluid communication between said valve chamber and said outlet and being dimensioned to receive and cooperate with said needle valve to provide flow control through the valve from said inlet port to said outlet port when said valve stem is moved from the closed position and to engage and provide a seal with the valve needle when the valve stem is in the closed position, and   actuator wheel means axially fixed on the outer end of said valve stem for substantially free rotation thereon, said actuator wheel means including internal thread means engaging and cooperating with said second external thread means on said valve guide whereby rotation of the actuator wheel means will produce axial movement of the valve stem to move the valve stem between the open and closed positions,   said generally radial surface of said valve seat engaging and cooperating with said substantially radial face to provide a positive stop for said valve stem when the valve is in the closed position.